70 lines
2.6 KiB
Python
70 lines
2.6 KiB
Python
# -*- coding: utf-8; -*-
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__all__ = ['Bunch']
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from collections.abc import Mapping, MutableMapping, Container, Iterable, Sized
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class Bunch:
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"""A bunch of named values.
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Can be used instead of a `dict` when `b.someattr` is more readable than
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`d['somekey']`. In terms of `collections.abc`, a `MutableMapping`,
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`Container`, `Iterable`, `Sized`.
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Example::
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b = Bunch(cat="meow", dog="woof")
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assert b.cat == "meow"
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assert b.dog == "woof"
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"""
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def __init__(self, **bindings):
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self._data = bindings
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self._reserved_names = []
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self._reserved_names = dir(self)
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def copy(self):
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return Bunch(**{k: v for k, v in self._data.items()})
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def __getattr__(self, name):
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return self._data[name]
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def __setattr__(self, name, value):
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if name in ("_data", "_reserved_names"):
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return super().__setattr__(name, value)
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if name in self._reserved_names: # prevent shadowing get, pop, et al.
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raise AttributeError(f"Cannot write to reserved attribute '{name}'")
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self._data[name] = value
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def __delattr__(self, name):
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del self._data[name]
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# Container, Iterable, Sized
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def __contains__(self, name): return self._data.__contains__(name)
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def __iter__(self): return self._data.__iter__()
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def __len__(self): return len(self._data)
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# Mapping
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def __getitem__(self, name): return self._data.__getitem__(name)
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def __setitem__(self, name, value): return self._data.__setitem__(name, value)
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def __delitem__(self, name): return self._data.__delitem__(name)
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def keys(self): return self._data.keys()
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def items(self): return self._data.items()
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def values(self): return self._data.values()
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def get(self, name, default=None): return self[name] if name in self else default
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def __eq__(self, other): return other == self._data
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def __ne__(self, other): return other != self._data
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# MutableMapping
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def pop(self, name, *default): return self._data.pop(name, *default)
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def popitem(self): return self._data.popitem()
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def clear(self): return self._data.clear()
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def update(self, **bindings): self._data.update(**bindings)
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def setdefault(self, name, *default): return self._data.setdefault(name, *default)
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def __repr__(self): # pragma: no cover
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bindings = [f"{name:s}={repr(value)}" for name, value in self._data.items()]
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args = ", ".join(bindings)
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return f"Bunch({args})"
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for abscls in (Mapping, MutableMapping, Container, Iterable, Sized): # virtual ABCs
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abscls.register(Bunch)
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del abscls
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